Embodiments relate to a data input/output (I/O) device, and more particularly to a data I/O device including a plurality of data units which can be simultaneously activated and operated at various speeds, and a system including the same.
The data I/O device includes one or more data units configured to store data. The data I/O device operates by communicating with an external part.
If several data units are coupled to an external part through a single I/O channel, all the data units included in the data I/O device may have the same operation speed. When the data units are sequentially coupled to the I/O channel, the data units may not simultaneously perform the I/O operation.